Amortization Explained: How Your Loan Gets Paid Off
Mike Starr
Founder, MortgageWizardTools · M.S. Organizational Management
Amortization is the process of paying off a loan through regular, scheduled payments that cover both principal and interest. An amortization schedule shows exactly how each payment is split and how your balance decreases over the life of the loan.
How Amortization Works
Each payment is calculated so that by the end of the term, your balance is exactly zero. The math ensures a level monthly payment, but the split between principal and interest changes every month.
In the early years, most of each payment goes to interest. In the later years, most goes to principal. This is not a trick — it is simply because interest is charged on the remaining balance, which is highest at the start.
Example: Year 1 vs Year 25
On a $350,000, 30-year, 6.5% loan:
| Principal Paid | Interest Paid | |
|---|---|---|
| Year 1 | $3,620 | $22,724 |
| Year 15 | $8,780 | $17,560 |
| Year 25 | $21,300 | $5,040 |
| Year 30 | $32,800 | $590 |
Why Amortization Matters
Understanding amortization helps you make better financial decisions:
- •Extra payments early have the biggest impact because they reduce the balance for the longest period
- •Refinancing resets the amortization clock — a new 30-year loan starts the interest-heavy phase over again
- •Selling early means you have built less equity than you might expect
Using an Amortization Schedule
Our Amortization Calculator generates a full schedule showing every payment, the principal-interest split, and your remaining balance at any point. This helps you plan extra payments, decide on refinancing, and understand your equity position.
Key Takeaways
- •Amortization is the gradual payoff of a loan through fixed payments
- •Early payments are mostly interest; later payments are mostly principal
- •Extra payments early in the loan save the most interest
- •Refinancing to a new term restarts the amortization schedule